The interpretation of both detections and non-detections
requires models of the emission and radiation transfer of the accretion tracers.
Despite decades of work by a few groups (e.g. [1]}, [2]}, [3]}),
the equivalent problem in low-mass star formation is not entirely solved.
The planetary case is even less well understood but there have been recent theoretical developments.
Indeed, [4]} and [5]} presented detailed models of the emission of tracers from an accretion shock on the circumplanetary disc (CPD) or the planet surface, respectively.
[6]} presented the first predictions of a model of magnetospheric accretion for low-mass stars (Classical T Tauri Stars; CTTSs) applied to planets.
